House Extensions Romford
Single storey rear and double storey extensions in Romford, planning, structure and build under one contract.
- Rated 4.9 from 31 reviews on MyBuilder
- Single-storey rear extension from £40,000
- Free site survey, itemised quote
GS Renovation plans and builds extensions across Romford, where the interwar semis and modern homes of RM1 sit on the generous plots typical of Havering's suburbs. We take on rear, side-return and wrap-around projects, from foundations through to a fully finished, decorated space.
In Romford, a single-storey rear extension typically starts from £40,000, or £2,000 to £2,800 per m² (indicative London ranges, Architecture for London, Resi, MyBuilder and Checkatrade, 2026). GS Renovation Ltd, a building contractor based in Potters Bar, does the work in Romford: the structural engineer we appoint designs the structure, we build it, and building control signs it off.
Price guide
| Work | Indicative London range |
|---|---|
| Single-storey rear extension | from £40,000 |
| Rear extension, per m² | £2,000 to £2,800 |
| Side return, per m² | £2,400 to £3,200 |
| Wraparound, per m² | £2,400 to £3,200 |
| Double storey, per m² | £1,800 to £2,600 |
| Basement extension | see the basement page |
Indicative London ranges (Architecture for London, Resi, MyBuilder and Checkatrade, 2026), not a quotation. Prices checked September 2026. Full breakdown: Extension Costs & Planning.
Quick estimate for Romford
Romford range: choose above
Rear and side extensions on Romford plots
The deep back gardens common to Romford's 1930s semis give real room to extend, which is why single storey rear and wrap-around extensions are so popular in RM1. We dig and pour the foundations, lay the groundworks, and build the shell, then install the steel beams that let us open the new addition into the existing kitchen or reception. Roof works, glazing and the full fit-out follow, all handled by one team.
Double storey extensions suit these houses too, adding a bedroom and a larger kitchen-diner while making the most of the wide plots. On a semi or terrace we consider the shared boundary from the outset, give you the drawings for any party wall notices you serve and set the design to respect your neighbour's light and outlook. Everything structural is signed off by Havering building control as the work proceeds.
Housing in Romford
About 20,230 homes are listed for Romford, and the mix is 65% houses to 35% flats, with 43% built after 1945, 42% in 1919 to 1939 and 15% earlier. 28% of homes here are terraced; a rear extension on a terrace in Romford digs foundations close to both neighbours, so notices to both are normal.
How deep and how large a Romford extension can go
Havering's prior approval route is for larger single storey rear extensions of up to 6m for an attached property or up to 8m for a detached property. On a Romford semi the attached figure applies, because the house is joined to its neighbour, and the route is not available in a conservation area. Prior approval gives the neighbours a chance to comment, so show them the plans before the application goes in. Check the Gidea Park Conservation Area boundary too. If your Romford house is inside it, the Article 4 Direction there removes Class A permitted development rights to enlarge, improve or otherwise alter a dwellinghouse to the front and sides, so even small changes on those elevations need a planning application.
Havering's building control charges rise with floor area. There is one band for an extension not exceeding 30 square metres and the next for over 30 but not over 60 square metres, so know which one the design sits in before it is frozen. Clearing the garden can add steps too. Havering asks anyone planning to demolish a building to tell the council at least six weeks before starting, and an old garage in the footprint of the new Romford extension may bring that into play, so ask building control. Put both in the programme at the start.
Planning and permitted development in Havering
Not every Romford extension needs a planning application. Many single storey rear projects fall under permitted development, provided they stay within the size, height and boundary limits, which the generous RM1 plots often allow. Where a design goes beyond those rights, or where the house sits in a spot with restrictions, we coordinate a full planning application to Havering Council with your designer.
Whichever route applies, building regulations always govern the structure, so foundations, beams, insulation and drainage are inspected regardless of the planning position. We advise honestly at the start on which path your property falls under, so there are no surprises. This clarity matters most on the interwar semis, where a wrap-around can quickly cross from permitted development into needing full permission.
Kitchen extensions in Romford
49% of the houses in Romford are semi-detached or detached, which usually leaves room for a kitchen extension across the full rear width, with a steel beam over the opening into the house. The fit-out is priced on its own page, kitchen renovation in Romford; the build figures are in the table above.
Side return extensions in Romford
Side returns belong to Victorian and Edwardian terraces, and only 15% of homes in Romford predate 1919, so they are the exception here; most extensions run across the full rear width instead. Our side return extension page covers the build in detail, with build rates of £2,400 to £3,200 per m².
Double storey extensions in Romford
Under permitted development a two-storey rear extension can go no more than 3 metres beyond the original rear wall and must stay at least 7 metres from the rear boundary, and in a conservation area it is not permitted development at all. Many gardens are too short for the 7 metre rule, so a double storey extension in Romford often needs planning permission from Havering Council. With 32% of homes here semi-detached or detached, the side of the house is often an option too. Romford Conservation Area was designated in 1968 to protect the Market Place and the group of old buildings at the western end of Market Place (council source). Our double storey extension page explains the build, at £1,800 to £2,600 per m² across both floors.
- Wrap-around extensions and infills
- Roof works and structural alterations at roof level
- First fix and second fix plumbing and electrics throughout
VOA Council Tax stock of properties, March 2025, for all 5 statistical areas in Romford. Counts rounded by the VOA.
Why Choose GS Renovation in Romford
Romford homeowners choose GS Renovation because we manage the whole extension, from foundations and steel to roof and decoration, under one roof. We advise clearly on whether your project is permitted development or needs a planning application to Havering Council, plan the programme around the party wall notices you serve on shared boundaries, and keep building control informed. Our founder's 30+ years on the tools backs every project.
- Foundation depth set after trial holes, drains and trees are checked
- Structural engineer instructed and coordinated on your behalf
- Weathertight shell reached before the fit-out begins
Built a new extension at rear of property. Laid foundations, drainage, raised floor, new roof and completed all fixtures and interior decoration…
Excellent service. George's knowledge and skills are the best in the market. He knows what he is doing, does really high quality work, gives good…
My husband and I are extremely pleased with the work. The standard of the work is outstanding and Saiid has a great eye for detail and will not leave…
FAQ
Frequently Asked Questions about House Extensions Romford
How accurate is a house extensions quote for a Romford house?
Accuracy on a house extensions quote in Romford comes from surveying, itemising and standing behind the total within £2,000 to £2,800 per m² for a rear extension (indicative). Quoting low to win a job and correcting it later is the commonest complaint about builders. GS Renovation prices in the order the work runs: the planning route is confirmed before drawings, and footings inspected before concrete. Anything unforeseen is costed before continuing at RM1.
What size extension is realistic on a Romford plot?
More than in inner London, because the gardens are generally longer. Houses around Romford often have space for a substantial rear extension without losing the whole garden, and side space as well on the semi detached stock. What limits it is usually daylight to the existing rooms and what permission allows rather than the plot. The design starts from what the house needs, not from the maximum footprint.
Is a two storey extension worth considering in Romford?
Where a bedroom is needed as well as living space, frequently yes. Building up as well as out at your Romford property adds far more floor area for a modest increase in foundation and roof work, though it is more likely to need planning permission and affects the neighbour's outlook more directly. The structural work is greater because loads carry through to the foundations.
What happens where a Romford extension foundation runs near the boundary?
The Party Wall etc. Act is usually engaged and you serve notice first. Excavating close to a neighbouring structure at your Romford property brings the work within the Act even where nothing touches the boundary wall. The owner serves notice, and where consent is not given surveyors are appointed and an award follows. The foundation design may be adjusted to suit what the award permits.
How does a Romford extension join the existing roof?
At a junction designed to shed water and stay watertight for the long term. Where a Romford extension meets the existing house, the abutment is flashed into the original brickwork and the falls are set so water runs away from the joint. A shallow or badly detailed junction is the first place a flat roof leaks. That detail is specified rather than left to the roofer on the day.
Does a Romford extension near a public sewer need full plans?
Yes, where it sits near one. Havering requires a full plans application rather than a building notice for work near a public sewer. On a Romford house the drain from the kitchen and bathroom often runs under the ground where the extension will stand. Lift the inspection chamber covers, or commission a short drain survey, before the footprint is fixed, because the line of the pipe can move a foundation, narrow the extension or bring in the sewerage company.
Is written pre-application advice useful for a Romford extension?
For a larger or unusual scheme it can be. Havering's written pre-application advice for householder extensions or alterations aims to reply within 20 working days of request. Havering does not offer householder telephone pre-application advice for properties in a conservation area or green belt, or for listed buildings. For a Romford house in one of those, the written route is the only one, so start it before the architect's drawings are finished.
Can a side extension work on a terraced house in Romford?
Usually not in the way it can on a semi. 28% of Romford homes are terraced houses and 32% are semi-detached or detached. A mid-terrace has no side to extend into, so the options are rear, or a side infill where the back addition is narrower than the house. An end-of-terrace or a semi with side access can take a side extension, subject to planning and the boundary.
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